The present invention relates to a testing device for determining the presence of occult blood in fecal matter, and more particularly to such a device for use in the home.
Over 100,000 persons in the United States are affected by cancer of the colon and rectum per year, occurring equally in both the men and women. When the number of colorectal cancers occurring each year is combined with the number of cancers occurring in other digestive organs, including the esophagus and stomach, such cancers of the digestive system account for more occurrences of cancer than any other single form of the disease. Contrary to many other forms of cancer, early diagnosis and treatment of digestive tract cancer does result in a cure rate of 80% to 90% of those persons affected by the disease. If, however, the disease is not detected until the later stages, the cure rate drops drastically to 25% or less. Thus, early detection of the disease is critical to successful treatment of digestive tract cancer.
Most, but not all cancers of the digestive tract bleed to a certain extent. This blood is deposited on and in fecal matter excreted from the digestive system. The presence of blood in fecal matter is not normally detected, however, until gross bleeding, that is, blood visible to the naked eye, occurs. Most advance cancers cause gross bleeding.
It is known that digestive tract cancers in the early stages also tend to bleed, giving rise to occult (hidden) blood in the fecal matter. Test equipment and test procedures have been developed for use by physicians in testing for the presence of occult blood in fecal matter. One of the most successful tests is manufactured and sold by Smith Kline Diagnostics, a division of Smith Kline Instruments, Inc. of Sunnyvale, Calif. under the trademark Hemoccult and disclosed in U.S. Pat. No. 3,996,006 issued to J. F. Pagano. Briefly, the Pagano test employs an absorbent paper impregnated with a guaiac reagent and encased in a special test slide having openable flaps on both sides of the test slide. To use the Pagano test slide, the physician or a lab technician must obtain a sample of fecal matter, smear it onto the guaiac impregnated paper by opening the panel on one side of the test slide, and thereafter close the panel. A panel on the opposite side of the test slide is then opened and a nonaqueous developing agent is applied to the guaiac impregnated paper. If occult blood is present in the fecal matter smeared on the opposite side of the paper, the guaiac reaction will dye the paper blue, providing a positive indication of the presence of blood in the fecal matter.
Although the Pagano test is excellent for use by physicians in their offices and by diagnostic laboratories, it is not the type of test which is readily adaptable for use by the ordinary person. It is cumbersome and requires too many manipulative steps, particularly the step of applying the nonaqueous developing agent to the guaiac impregnated paper.